Comparative Analysis Of Arterial And Venous Blood Gas Changes In Patients With Different Prognosis After CPR

Objectives:For exploring the changes in arterial and venous blood gas in patients with different prognosis,we compare the data of indicators at 0min,30min,1h,2h,which will be extract from analyzation of the blood gas parameters?PH?PCO₂?PO₂?SO₂?of arterial and venous blood in patients undergoing cardiopulmonary resuscitation after clinical cardiac arrest.Methods:A total of 70 patients undergoing cardiopulmonary resuscitation from Department of Emergency and Critical Care Medicine at the Affiliated Hospital of Yan'an University from 2015 to December 2017 were selected and divided into three groups according to the prognosis of the patients:group A,death group,died after 30minutes CPR,or successful recovery but restoration of spontaneous circulation time was less than 2 hours,which contains 36 patients;Group B,successful CPR and ROSC time was over 2 hours,but eventually,within 24 hours,died,brain died or stayed in persistent vegetative state,which contains 20 patients.;Group C,survival group,which require successful CPR,and ROSC,and eventually recovered from hospital which contains 14patients.All three group of patients met the criterion such as over 18 years old with cardiac arrest,rescued strictly in according to the Cardiopulmonary Resuscitation?CPR?and Cardiovascular First Aid guidelines issued by the 2015 American Heart Association?AHA?,and patients with spontaneous circulation recovery were given general Basic life support treatment,including:endotracheal intubation,oxygen inhalation,rehydration,replenishment of water and electrolyte,improvement of microcirculation,etc.,and active treatment of primary disease.We only detected arterial and venous blood gas of group A after cardiac arrest,which is blood gas at 0min,and group B,C were detected PH,PO₂,PCO₂,SO₂ of arterial and venous blood at 0min,30min,1h,2h,and calculated AVPH,AVPO₂,AVPCO₂ and O₂UC=?SaO₂-SvO₂?/SaO₂.SPSS22.0 software was used to perform statistical analysis on each index,and comprehensively evaluate the changes in blood gas analysis indicators of arterial and venous blood and the degree of difference,and predict its clinical significance in patients after CPR.Using?=0.05 as the standard,P<0.05 indicated that the difference was statistically significant.Results:1.The comparison of patients'basic data,the ages of group A,B,and C and the time of ROSC recovery were statistically different?P<0.05?.The patients in different groups had no significant differences in gender,CPR onset time,and underlying disease among the three groups?P>0.05?.There was no significant difference in age between the monitoring indicators?P>0.05?.2.Comparison among the indicators of arterial and venous blood gas at 0min in patients and each prognostic group2.1 PH value:At 0min PH of arterial blood,after comparison of three groups,thedifference was not statistically significant?P>0.05?;PH and AVPH of venous blood,the difference was statistically significant?P<0.05?.And then cross comparing,there was a statistical difference between group A and group B?P<0.05?.There was no significant difference between group C and group A with B?P>0.05?.2.2 PCO₂ values:The differences of PaCO₂,PvCO₂,and AVPCO₂ in eachprognostic group were statistically significant?P<0.05?.After cross comparisons,PvCO₂and AVPCO₂ were statistically different between group C and group A,B,and there was no statistical difference between group A and group B.As for PaCO₂,there was no statistical difference among group A,B and C,but there was a statistical difference between group B and group C.2.3 PO₂ values:There was no significant difference in PaO₂ and AVPO₂?P>0.05?.In PvO₂,the difference was statistically significant?P<0.05?,and the difference between A and B groups was statistically significant?P<0.05?.There was no significant difference between C and A,B?P>0.05?.2.4 SO₂ values:There was no statistical difference between SaO₂ and AVSO₂.InSvO₂,there was statistically significant?P<0.05?,and the difference between A and B groups was statistically significant?P<0.05?.There was no significant difference between C and A,B?P>0.05?.3.Analysis PH of arterial and venous blood gas:3.1 Overall situation:arterial blood gas:group A,acidosis,accounting for 63.89%of the total number of all cases,including 18 patients with PH?7.20,9 patients with PH<7.00;alkalosis,accounting for 30.56%,there are 8 cases with PH?7.50.Group B,alkalosis,60.00%of the total,10 cases with PH?7.50;acidosis,35.00%,3 cases with PH<7.00;group C,acidosis,64.29%of total cases,there are no case with PH<7.00.venous blood gas:group A,acidosis,accounting for 63.89%of the total number of cases,of which 23 cases with PH?7.20,20 cases of patients with PH<7.00;alkalosis,accounting for 30.56%,PH?7.50 in 13 cases.In group B,alkalosis accounted for60.00%of the total number,11 cases had PH?7.50;acidosis,about 35.00%,and 3 cases had PH<7.00.In group C,acidosis accounted for 64.29%of the total cases and 0 cases of PH<7.00.3.2 Arterial blood gas:When PH<7.35,there was a statistically significantdifference among three groups?P<0.05?;by performing a pairwise comparison analysis,it was concluded that there was a statistically significant difference between A and C groups?P<0.05?.There was no significant difference between B and C,A?P>0.05?.When PH>7.45,there was no significant difference among groups?P>0.05?.When pH was between 7.35 and 7.45,there was no significant difference among three groups?P>0.05?.3.3 Venous blood gas:When PH<7.35,there was a statistically significantdifference among three groups?P<0.05?;a pairwise comparison analysis resulted in:A significant difference between group A and B?P<0.05?,and there was no significant difference between C and B,A?P>0.05?.When PH>7.45,the difference among three groups was statistically significant?P<0.05?.Cross comparing,it was concluded that there was a statistically significant difference between A and C groups?P<0.05?,and there was no significant difference between B and A,C?P>0.05?.When PH was between7.35 and 7.45,there was no significant difference among three groups?P>0.05?.4.Comparison of arterial and venous blood gas in each time point4.1 PH value:PH of arterial and venous blood,there was no significant differencebetween each time point of B and C groups?P>0.05?.Resulting from trend change,PH value of arterial blood in both groups of patients in 0min³0min are decreasing,besides data in group B decreased more significantly than group A,while in the 30min²h,data showed an upward trend,and patients in group C recover faster comparing with group B.Venous blood:In group B,there was a significant descending peak in 0min³0min,and then slowly increased,while patients in group C showed a continuous upward trend.4.2 PCO₂ values:PCO₂ in arterial and venous blood between groups B and C ateach time point,statistically significant?P<0.05?;and there was a statistically significant difference in time distribution between group B and C.The difference between the two groups at 0min and 30min was statistically significant.It can be seen that the change of trend showed that after the cardiopulmonary resuscitation,the mean value of PCO₂ in arterial and venous blood had a rising phase and then drop.The PCO₂ value in the vein group is higher than those in the arterial group,and the PCO₂ level in group B is greater than group C.4.3 PO₂ values:There were statistical differences between the time points ofarterial and venous blood in B and C groups?P<0.05?;and in group C patients,PaO₂?PvO2 were compared at different time points in their development,and a statistical difference?P<0.05?was occurred.Changes in trends showed that the arterial and venous PO₂ of both groups are on the rise,and the changes in group B are faster than those in group B.4.4 SO₂ values:There was no significant difference of indicators at all time pointsof arterial and venous blood in group B and C?P>0.05?.However,there was a statistically significant difference in group C at different time points?P<0.05?.The trend change chart showed that there was an upward trend in group C.In group B,the SvO₂value showed a downward trend from 30 minutes to 2 hours,while the SaO₂ value rose first and then decreased.4.5 Comparison of the AVPH,AVSO₂,AVPO₂ and AVPCO₂:AVPH increased first and then decreased,but the magnitude of decline in group C was greater than that of group B;AVSO₂,group B showed an upward trend,while group C showed a decreasing trend.AVPO₂ showed an upward trend,but group B was always larger than group C;AVPCO₂,group B had a rising period and then began to decline.Compared with group C,the survival group,group B was always in high level status,while group C composed a slowly declining.5.Oxygen utilization rate:The levels of oxygen utilization in the three groups were0.426±0.219,0.335±0.161,and 0.298±0.433,respectively.Oxygen utilization varies from high to low with different level of prognosis.Patients with different prognosis have different oxygen utilization rates.Conclusion:1.Patients with cardiac arrest,experiencing a sharp decline in circulating blood volume,will develop varying degrees of acid-base imbalance,mostly with acidosis,in which venous blood acidosis is more serious than the arterial blood acidosis.And the degree of alkalosis is also serious;2.After cardiac arrest,arterial blood and venous blood were changed in patients with different prognosis,but venous blood was more sensitive to arterial blood than that of arterial blood in PCO₂,PO₂,and SO₂.3.After CPR,the patients with the same prognosis had greater changes in PH,PCO₂,PO₂,and SO₂ of venous blood than arterial blood at each time point of rehabilitation;4.After CPR,patients with different prognosis had greater changes in arterial and venous blood gas ratio than patients with poor prognosis at various time points of recovery.5.The worse the prognosis of the patients,the higher the oxygen utilization rate;on the contrary,the oxygen utilization is low,the prognosis is good.